| The outcropping Cretaceous Tres Pasos Formation, Chile, provides an opportunity to examine the architectural complexities of a deep-water slope channel system. Present towards the toe of a graded slope clinoform, the 2.5 km long outcrop is crosscut by numerous gullies, which provide exceptional exposures of channel bodies and allow projection into 3-D. Channels are characterized by: (1) erosive bases that define channelform geometries 6-15 m thick and ∼300 m wide; (2) a basal siltstone drape; (3) thick-bedded turbiditic sandstone in axes; and (4) thin-bedded turbidites towards the margins. This architecture records punctuated incision and sedimentary bypass followed by depositional stages where channels are in-filled by collapsing turbidity currents. Eighteen channels are delineated, vertically stacked and amalgamated into one another. The overall stratigraphic architecture, comprising a composite sedimentary body 130 m thick and 1000 m wide (along strike), is comparable to seismically imaged channel systems from the world's continental margins. |
